In order to bring about just and informed decisions, evidentiary and procedural rules
have been established by tribunals to permit the inclusion of relevant evidence and
argument and the exclusion of all other considerations. The expression by a lawyer of his
personal opinion as to the justness of a cause, as to the credibility of a witness, as to
the culpability of a civil litigant, or as to the guilt or innocence of an accused is not
a proper subject for argument to the trier of fact. It is improper as to factual matters
because admissible evidence possessed by a lawyer should be presented only as sworn
testimony. It is improper as to all other matters because, were the rule otherwise, the
silence of a lawyer on a given occasion could be construed unfavorably to his client.
However, a lawyer may argue, on his analysis of the evidence, for any position or
conclusion with respect to any of the foregoing matters.